Mongo

ARRGH! Project shelved until I take care of maintenance and other issues right now.

Laust Pedersen

Hopefully as an inspiration, here is some of what did to my Espada engine some 14 years ago.
The Webers are de-gutted and act as throttle bodies only. The engine management system is a very early TEC-1 unit (with firmware upgrades).

As “thedge” eluded to, the vacuum/pressure (load signal) can be taken from a cross-tube, which in this case was built in to the manifold (for brake vacuum). However it is far from “easy”. The signal will very likely oscillate, but can be adequately dampened by careful selection feed hole size from the runners to the cross tube, volume of the tube and sensor outlet hole size.
Too large feed-holes and you spoil the resonance characteristics of the intake runner and too small feed-holes will delay the signal (not good if a MAP system is used). Similar considerations should be applied to the cross tube volume and outlet hole size.

I can assure you that the Porsche 951 engineers have been through this exercise in designing our intake manifolds with a very stable signal.

Btw, going to a hotter cam will reduce the vacuum signal with some obvious and non-obvious side effects.

Oh, the throttle response is amazing.

Laust

RobHeinl

Gremlin- send me an email at rdh190@gmail
I'm in Allentown, PA and have some thoughts for you on your project.
I'd PM you but apparently I'm not I'm not allowed to yet (Newbie) Also it appears that I can't put an email address in my post either...

Mongo

Project back online. I got funds now!

I'm gonna look into Extrudabody to see what they have...

http://www.extrudabody.biz/servlet/t...its/Categories

Mongo

I managed to pick up a set of Suzuki GSXR 600 throttle bodies last night for this project. From what I have seen through pictures, this appears to be the best choice for the conversion on the 944 since it has all the vacuum line locations in the right spot.

I'm going to need another wiring harness from a 944 to chop up though in order to lengthen the TPS harness and AFM harness as a result of relocating the throttle linkages.

evil 944t

I have a set of GSXR 750's for sale. $100+ shipping. They are true ITB's that can be spaced properly.

Mongo

The 2001 ITBs I bought can be spaced too. Just picked the set up for $35 off ebay

evil 944t

thanks, that really helped out my sale.. ps - I paid $100 for mine. I'm just not using them..

Mongo

$100 is still a very good deal. I lucked out by NOT getting sniped. The last set of GSXR ITBs I was bidding on went for $300! Anyone willing to tackle an ITB project and is looking to spend $100 or less on a set would get a good deal.

Mongo

Alrighty. After taking some measurements and finding out the specs on the GSXR throttle bodies, I'm out in search for 4 velocity stacks. I am looking for an inner diameter of 45mm. If anyone knows where to get some good velocity stacks that can be welded, let me know. Thanks!

Mongo

It looks like I'm going to need a 944 Turbo manifold rather than an NA manifold for these throttle bodies due to spacing.

If anyone has a spare 951 manifold please PM me.

azmi951

My frind made a new manifold with ITBs for his 300ZXtt. he use motorcycle throttle bodies too. His creation is great looking. and made me think of the same things discussed here.

Mongo

VERY URGENT UPDATE AND HELP NEEDED:

I have run into a bit of a debacle when it comes to intake port diameters and the throttle bodies.

Here is the situation:

The throttle bodies taper from 41mm to 38mm after the butterfly. It's essential that I use the 41mm side for induction due to the location of the vacuum ports. The bad news is I'm losing 3mm inner diameter going into the intake ports.

My options are this:

1) Reduce the intake runner I.D. to 38mm until it expands enters the 41mm intake port.

2) Use 41mm intake runner tubing after the 38mm throttle body and use expanding silicon collars or sleeves to merge together.

Engine builders and intake builders: Your thoughts and suggestions are welcome. I need a little help here.

UncleMaz

Nice save. Bump.

MAGK944

Just some pics that were gathering dust in my computer. The throttle bodies in the drawing are from a company in England www.dtafast.co.uk, don't know the 16v configuration or where I got the picture from. Any help to anyone?